Mercedes' approach to F1 2017 tyre testing probably wrong

With Ferrari having started this year so strongly - and the characteristics of its SF70H so well suited to the new wider tyres - there have been mounting suspicions about the benefits the Italian team gained from the extensive running for Pirelli that Sebastian Vettel did with a mule car in 2016.

In contrast to Vettel's 2228km of Pirelli testing last year, Rosberg did 209km while Hamilton did just 50km.

Wolff, whose own team is struggling to master the tyres, he is convinced Ferrari gained an edge in having someone as established as Vettel throw himself fully into the programme.

"It was definitely an advantage for Ferrari that they had Vettel doing it, because with his experience, he was a credible test driver," said Wolff, whose own testing efforts were led by then-rookie Pascal Wehrlein.

"If you are driving your car and you are a Pirelli engineer and you have Vettel giving you an input, it is different to Pascal Wehrlein."

Wolff said that the decision to use Wehrlein came about because neither Hamilton nor Rosberg wanted to be distracted from their very intense title battle last year.

"The situation was different with us last year, because Nico and Lewis were in a championship fight, back then, with the current car," added Wolff.

"Both of them said that testing next year's car, with next year's tyres, was something that would at least harm them in their focus of the world championship in 2016. So it was understandable.

"If I could turn back time, I would probably push a bit harder for them to drive the new tyres, but we were in a different situation to the Ferrari drivers."

Wolff comments about the benefits that his team missed are in contrast to what his drivers felt earlier this year, with Hamilton saying that he did not think testing with the mule cars would have helped him at all.

"I'm so glad I didn't do that testing, because the car is so different," said Hamilton earlier this year.

"I did a few laps in the Abu Dhabi test in the 2015 car and it was so much different to this car," he said.

"It would have been a waste of my time. I'm glad I didn't do it. It made no difference.

"The fact is the [mule] car had so much less downforce and it was lighter than the car we have today, so it wouldn't have put the tyres in the same window.

"The stuff I would have learned then, I would have to undo it and learn again."